1. Field of the Invention
The invention relates to packaged products and means for providing rupturable seals to divide plastic containers into a plurality of compartments. More particularly the present invention provides a rupturable seal, comprising melt-blown micro-fibers, that separate by application of force, causing the seal to rupture to provide an opening that allows interaction of materials previously isolated in separate compartments of a plastic container.
2. Description of the Related Art
A single container may be used for storage of materials that react together if allowed to come into contact with each other. Typically, the single storage container includes means, for example sealed boundaries or barrier strips, and the like, to prevent contact between the reactive materials until there is a need for the product of reaction. The use of seals and barrier strips provides means for separating containers, particularly plastic containers or packages into a number of separate compartments. A variety of liquids or mobile reactive components may be isolated in individual compartments. Disruption of a barrier between compartments provides a pathway for reactive components to intermix and react together. Reaction may be encouraged by hand manipulation of a flexible package.
The use of multi-compartment plastic packages is known for containment of reactive materials including reactive liquid monomers that require separation from activator materials that convert the liquid monomers into cured resin materials. A typical combination of reactive components comprises as a liquid epoxy monomer separated from a stable mixture of a liquid polysulfide polymer and an amine activator for the epoxy monomer. When mixed together, these materials undergo exothermic reaction to produce a heat-resistant, tough resinous product that finds use as an electrical insulating material.
U.S. Pat. No. 2,932,385 discloses a multi-compartment plastic package suitable as a container that keeps a liquid epoxy monomer composition separate from a liquid polysulfide polymer. The package includes two sheets of a thermoplastic film fusion bonded together along the outer edges of the film and divided into compartments by heat-sealing a breaker strip between the films so that it extends to the fused edges of the films. A breaker strip is weaker physically than either of the films, which allows it to break, under stress, before rupture of the fused edge seals of the plastic package. A related patent (U.S. Pat. No. 3,074,544) describes several methods for forming multicompartment packages using a variety of sealing strips.
Other references to multi-compartment plastic packages may be found in, for example, U.S. Pat. No. 2,756,875, U.S. Pat. No. 2,916,197, U.S. Pat. No. 3,809,224, U.S. Pat. No. 4,961,495, and U.S. Pat. No. 5,287,961. Other materials may be stored in multi-compartment plastic containers as described in U.S. Pat. No. 2,971,850 that identifies a multi-compartment package including a rupturable membrane to separate the components of an enzyme system. The package preserves enzyme activity before rupture of the membrane and reaction between the enzyme and an appropriate substrate material.
Regardless of the availability of sealing strip structures, useful for providing separation between compartments of plastic containers, a need exists for seal forming material to lower the cost, improve consistency and increase the efficiency of processes used for manufacturing multi-compartment plastic storage bags having increased shelf life.